This invention relates to a novel compound, a resin composition suited as molding materials, insulating-layer materials and adhesive materials, a curing accelerator for the resin composition, and an electronic component device obtained by encapsulating device components with the resin composition.
Epoxy resin is conventionally used in a wide range as molding materials, insulating-layer materials and adhesive materials, and epoxy resin compositions are in wide use in the field of the encapsulation of device components in electronic component parts such as transistors and ICs (integrated circuits). This is because the epoxy resin has properties such as molding properties, electrical properties, moisture resistance, heat resistance, mechanical properties and adhesion to component inserts which are well balanced.
As curing accelerators for epoxy resin, Japanese Patent Application Laid-open KOKAI No. 55-5929, No. 56-94761, No. 56-131620, No. 58-57427, No. 57-210647, No. 59-136321, No. 61-151231, No. 63-12627, No. 63-20325, No. 63-210121, No. 1-105562, No. 1-236263, No. 1-236264, No. 2-34627, No. 5-9268, No. 5-198940, No. 6-228414, No. 7-228664, No. 7-188395, No. 8-3280, No. 7-330868, No. 8-92355, No. 8-92356, No. 8-157565 and No. 8-157564 disclose 1,8-diazabicyclo[5.4.0]undecene-7, or its phenolic salt, phenolic resin salt, aromatic carboxylate, aromatic sulfonate, fatty acid salt or carbonate. Japanese Patent Application Laid-open KOKAI No. 3-116958 discloses silicon derivatives of 1,8-diazabicyclo[5.4.0]undecene-7. Use of these curing accelerators, however, has involved a problem that the epoxy resin is affected by humidity in service environment and may have a low curing performance depending on moisture absorption to cause various faulty molding such as faulty mold release, runner break and gate break.
Japanese Patent Applications Laid-open KOKAI No. 62-81416, No. 1-65116 and No. 3-9919 also disclose methods of use of 1,8-diazabicyclo[5.4.0]undecene-7 or a salt thereof in the form of its mixture with a triorganophosphine. Japanese Patent Applications Laid-open KOKAI No. 62-16484, No. 1-38416, No. 2-189331, No. 2-240131, No. 4-65420, No. 4-85321, No. 4-91121, No. 4-96922, No. 4-96930 and No. 8-109246 disclose methods of use of 6-dialkylamino-1,8-diazabicyclo[5.4.0]undecene-7 or salts thereof. Japanese Patent Applications Laid-open KOKAI No. 59-8721, No. 59-8722 and No. 3-16243 disclose methods of use of 1,5-diazabicyclo[4.3.0]nonene-5, and also Japanese Patent Applications Laid-open KOKAI No. 63-146919, No. 2-189330 and No. 2-240130 disclose methods of use of a guanidine compound. These methods promise a superiority in rapid curability and curability under moisture absorption but, on the other hand, have involved a problem that a difficulty in molding as exemplified by faulty filling may occur because of a short pot life, an increase in melt viscosity and a decrease in flow properties or that the performance of molded products may lower, e.g., gold wires of IC chips break to cause faulty conduction. Accordingly, under existing circumstances, epoxy resin compositions which employ such a technique and molding materials for encapsulation which make use of such resin compositions must be stored and transported under refrigeration, and require a high cost.
Japanese Patent Applications Laid-open KOKAI No. 59-75923, No. 62-246925 and No. 3-26901 disclose that tetraphenyl borate of 1,8-diazabicyclo[5.4.0]undecene-7 is effective for the improvement of pot life. This tetraphenyl borate has so strong an ionic bond and so high a melting point as to have a low dispersibility, bringing about a good pot life. It, however, can not exhibit any good curability.
In addition, in recent years, as the greatest problem in molding materials for encapsulating semiconductors such as ICs and LSIs (large-scale integrated circuits), there is a problem of what is called solder reflow cracking, which is cracking caused when packages are assembled. In order to improve reflow cracking resistance, resin compositions are proposed which contain an inorganic filler in a large quantity. The inorganic filler, however, must be mixed in a quantity limited because its use in a large quantity causes a lowering of flow properties at the time of molding. Hence, this technique can not be expected to bring about any remarkable improvement in reflow cracking resistance. Accordingly, as a way of overcoming such a problem, it is proposed in Japanese Patent Application Laid-open KOKAI No. 9-157497 that an addition product of triphenylphosphine with 1,4-benzoquinone is used as a curing accelerator, which, however, has involved the problem of a short pot life.
As discussed above in detail, any conventional curing accelerators can not satisfy all the rapid curability, curability after moisture absorption under moist condition, pot life and flow properties of epoxy resin compositions.
The present invention was made taking account of the problems discussed above. An object of the present invention is to provide an epoxy resin composition having all the rapid curability, curability after moisture absorption under moist condition, pot life and flow properties in a good state, a curing accelerator used therefor, an electronic component device having device components encapsulated with such a composition, and a novel compound suited as the curing accelerator.
The present inventors have discovered that the rapid curability, curability after moisture absorption under moist condition, pot life and flow properties of epoxy resin compositions can be improved by mixing a nitrogen-containing compound obtained by the addition of a specific amidine compound with a specific quinone compound, thus they have accomplished the present invention.
To achieve the above object, the present invention provides a nitrogen-containing compound which is an addition product of an amidine compound represented by the following Formula (XXa) or (XXb) with a quinone compound represented by the following Formula (II). 
In Formula (XXa) or (XXb), R1 and R2 each represent a hydrogen atom, an amino group or a monovalent organic group having 1 to 20carbonatoms. The organic group may preferably have 2 to 15 carbon atoms, and more preferably 2 to 10 carbon atoms. R3 and R4 each represent a divalent organic group having 1 to 20 carbon atoms, which may preferably have 2 to 15 carbon atoms, and more preferably 2 to 10 carbon atoms. 
In Formula (II), R5 represents a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms, and k and p represent an integer of 0 to 2 and an integer of 0 or 1, respectively.
R1 and R2 may each preferably be selected from a hydrogen atom and substituted or unsubstituted alkyl, aryl, aralkyl, alkenyl and alkoxyl groups. R3 and R4 form part of the ring structure, and may preferably be selected from a substituted or unsubstituted, saturated or unsaturated hydrocarbon group, and a saturated or unsaturated hydrocarbon group containing a carbonyl linkage, an imino linkage or an ether linkage. R5 may preferably be selected from a hydrogen atom and an alkyl group, an alkoxyl group, an aryl group and an aralkyl group which have 1 to 6 carbon atoms.
As stated above, the groups represented by R1 to R4 may be those in which a substituent is further bonded to the basic structure of alkyl group, aryl group, aralkyl group, alkenyl group or alkoxyl group. As examples of such a substituent, it may include alkyl groups such as a methyl group and an ethyl group, aryl groups such as a phenyl group and a naphthyl group, alkoxyl groups such as a methoxyl group, an ethoxyl group and butoxy group, a hydroxyl group, hydroxyaryl groups, an amino group, alkylamino groups, cyanoalkyl groups and alkylaryl groups.
The above amidine compound may preferably be a compound represented by the following Formula (I). 
wherein R6 is selected from a hydrogen atom and an alkyl group, a dialkylamino group, an aryl group and an aralkyl group which have 1 to 12 carbon atoms; and m and n represent integers of 2 to 5 which are independent from each other.
Of the compounds represented by Formula (I), 1,8-diazabicyclo[5.4.0]undecene-7 and 1,5-diazabicyclo[4.3.0]no nene-5 are particularly preferred, and these may be used alone or in combination. As the quinone compound represented by the above Formula (II), 1,4-benzoquinone and 2,5-toluquinone are preferred, and these may be used alone or in combination.
The present invention also provides a nitrogen-containing compound represented by the following 
In the above Formula (XXIa) or (XXIb), R1 and R2 each represent a hydrogen atom, an amino group or a monovalent organic group having 1 to 20 carbon atoms. The organic group may preferably have 1 to 15 carbon atoms, and more preferably 1 to 10 carbon atoms. R3 and R4 each represent a divalent organic group having 1 to 20 carbon atoms, which may preferably have 2 to 15 carbon atoms, and more preferably 2 to 10 carbon atoms. R5 represents a hydrogen atom or a monovalent organic group having 1 to 6 carbon atoms, and k and p represent an integer of 0 to 2 and an integer of 0 or 1, respectively.
In Formulas (XXIa) and (XXIb), the double bonds and positive electric charges are depicted in localized forms for the sake of convenience, to which, however, the present invention is by no means limited. The double bonds and positive electric charges (and the hydrogen atoms in the case when R1 or R2 is hydrogen) may be delocalized between the two nitrogen atoms of the amidine group. Also, depending on the structure of R3 and R4, they may be delocalized inside the heterocyclic ring constituted of these organic groups and the amidine group.
The resin composition containing the nitrogen-containing compound of the present invention may also be used as a molding material for encapsulation and a in multilayer or adhesive material. For example, epoxy resin compositions prepared using the nitrogen-containing compound of the present invention as a curing accelerator for epoxy resin and phenolic resin have superior rapid curability, curability after moisture absorption under moist condition, pot life and flow properties, and hence are suited as molding materials for encapsulation, laminate sheet materials and adhesive materials. Besides, such compositions may also be used in a wide field as, e.g., anisotropic conductive film materials and insulating materials. Accordingly, the present invention provides a resin curing accelerator containing the nitrogen-containing compound of the present invention.
In particular, a molding material making use of the nitrogen-containing compound of the present invention as the curing accelerator for epoxy resin and phenolic resin and compounded with a filler is suited for its use as a material for encapsulating electronic component devices. Accordingly, the present invention provides the epoxy resin composition containing the nitrogen-containing compound of the present invention and an electronic component device having device components encapsulated with the composition.